Another Poliovirus Detection In London

The Global Polio Eradication Initiative recently reported one circulating vaccine-derived poliovirus type 2 (cVDPV2)-positive environmental sample was detected in wastewater in the United Kingdom.

As of January 8, 2025, the UK Health Security Agency (UKHSA) says there is no evidence of community transmission, and the polio risk to the public in London is low.

Poliovirus surveillance is undertaken at 26 sites in the UK, with monthly sampling.

During November 2024, VDPV2 was detected in 1 sample from East Worthing Sewage Treatment Works (which covers some of West Sussex local authority and adjacent areas), in 2 samples from Leeds Knostrop Sewage Treatment Works, and 1 sample from the London Beckton Sewage Treatment Works.

As part of routine surveillance, poliovirus is detected occasionally in the UK. Brief detections do not require any public health action, as these are generally one-off findings due to:

Individuals being vaccinated overseas with the live attenuated oral polio vaccine (OPV) enter the UK and ‘shed’ traces of the ‘vaccine-like’ poliovirus in their feces. Immunosuppressed individuals may also shed the virus for an extended period.

And visitors entering the UK from a country where vaccine-derived polioviruses have been circulating.

The same circulating VDPV2 strain has also been recently found in sewage samples from sites in other European countries in 2024. Several countries offer OPV on exit as part of their response to polio outbreaks.

The UK switched from the OPV to the Inactivated Polio Vaccine (IPV) in 2004.

In the United States, the IPV has been offered since 2000.

The U.S. CDC recommends that international travelers be fully vaccinated against polio before visiting countries of concern. In 2025, travel clinics and pharmacies will offer the IPV.